The present invention relates to a portable modular light diffusion box, and in particular such a box which includes light diffusion frame(s) and the capacity to contain multiple lights.
In the entertainment industry including motion pictures, television and theatrical arts, as well as in the photographic industry and other fields, it is necessary to light a set, stage or other area. Often, particularly for an indoor set in the motion picture and television industries, the key (primary) lighting is provided at the back corners of the set (opposite where the camera and audience, if any, will be) to avoid boom (sound equipment) shadows and a fill light from the front in accordance with a theory known as back cross key lighting.
While back cross key lighting is used in almost all sitcoms, there are some inherent drawbacks to the system. One problem is that the xe2x80x9ckeyxe2x80x9d or strongest light comes from the top/back (upstage) portion of the set, so there are invariably shadows thrown from the people and objects on the set onto each other. Also, in many cases there are shadows from a person""s facial features that fall upon that person""s face, such as nose shadows. The strong (xe2x80x9chardxe2x80x9d) light coming from the back also creates hot rims around people and is especially objectionable on bald or light-haired individuals. This hard light, which is traditionally used, can also create unwanted microphone boom shadows.
In studio photography, light diffusion gel frames have been used to soften lighting by diffusing the light. These frames have been typically individually mounted in front of or to a lighting instrument.
Conventional wisdom is that the lights are mounted on a stand, on a pipe, or on typical set scaffolding known as a green bed. As there are numerous lights on a set, and as providing a diffusion screen on each light is cumbersome, and as it is further cumbersome to change such screens and to align such lights to properly cooperate, the use of individually mounted diffusion devices is not practical or economical for some set lighting, especially sitcoms.
Examples of individually mounted diffusion gel supporting members are shown in U.S. Pat. No. 5,651,602 to Joseph N. Tawil, issued Jul. 29, 1997, and U.S. Pat. No. 4,446,506 to Raymond G. Larson issued May 1, 1984. These require special brackets or rings to mount to the lighting instrument, and are often dependent on the type of light.
A diffusion device has been known to be used with multiple lights, such as in U.S. Pat. No. 4,855,874 to Thomas A. Waltz issued Aug. 8, 1989. The Waltz patent discloses a light modifier which is inflatable and surrounds multiple lights attached to a stand or to other support rods which are not part of the inflatable device. The device itself which provides light diffusion must be entirely changed to change the light diffusion effect, and it has limited ability to control and direct light. It is therefore impractical to use for set lighting.
U.S. Pat. No. 5,128,838 to Muriel H. Brandess issued Jul. 7, 1992, discloses a photographic filter-holding apparatus that has a mechanism for holding a filter in front of a light. In one embodiment there are two lights, but each light has a separate filter, and it also requires a special mounting structure.
Even when diffusion is used, often expensive fresnel lights are used with it. These are focusable between xe2x80x9cspotxe2x80x9d and xe2x80x9cfloodxe2x80x9d conditions, and provide a useful light source because you can change the pattern and intensity of the light when it is not heavily diffused, allowing for a tight xe2x80x9cspotxe2x80x9d of hot light, a wide flood of lesser intensity, or a selectable middle ground. It is interesting to note that when projected through heavy diffusion, this function is neutralized. However, fresnel lights have drawbacks. They are expensive, inefficient and heavy.
What is needed is a box which can diffuse and control light from multiple lights in such a way that the box and lights are stable, preferably avoid the need for expensive lighting instruments such as fresnel (focusable) lights, and provide soft, diffused light preferably from multiple instruments such as par cans (xe2x80x9cparsxe2x80x9d), to enable the use of front projected lighting as the key or primary lighting for a stage or set.
What is also needed is a device that can project soft key light in a controllable way deep into the set evenly from front to back and side to side while having a compact profile to allow for cameras underneath and viewers behind. The light would be parallel to and under the microphone booms thus eliminating boom shadows. The light would also come from a similar angle as the cameras eliminating or xe2x80x9cburyingxe2x80x9d shadows behind the objects themselves.
Certain lights have been made for overhead lighting, i.e., above a set or other item needing light. However, these do not provide an efficient soft projected and consistent light. For example, one configuration known as the xe2x80x9cchicken coopxe2x80x9d has six 1000-watt bulbs shaped much like household bulbs. Light is unevenly pushed through the lamps themselves and bounced off the light shell, resulting in a very mixed source with limited projection. Even if a diffusion screen is used, the light is inconsistent and the bulbs cannot be individually controlled.
Sometimes, a long cylindrical fabric sheath with a roughly 30-inch diameter opening is placed around some open globes in a wheel type configuration known as the space light. The sides of the sheath can be blackened. The problem with this light as an overhead light is that it uses a lot of energy for very little output. Much of the light is absorbed in the black sheaths and not output from the opening at the bottom of the sheath. The source, being just globes, is not internally or externally focused to project well through the exit port as described.
Light diffusion elements have been constructed of cardboard or other consumables in a jury-rigged fashion for a long time. There also is a company known as Chimera which markets cone-shaped soft tent-like members for attachment in front of a lighting source, typically a single fresnel light. However, none of the extensive art combines a box with interchangeable diffusion frames and standard light mounting rods facilitating the use of multiple par cans, e.g., four or more, to create a deeply projected but soft light that is consistent from near to far. Moreover, none put all of these elements together with built-in lights in a way that enables use of inexpensive light-weight lights with high output to obtain a soft projected light.
What is needed is a high-output, projected soft light from a modular system using multiple lights. What is also needed is such a system that is provided in a lightweight, foldable structure which readily mounts to standard mounting equipment such as stands, scaffolding or other existing support structure. What is also needed is a way to obtain soft projected light from inexpensive, non-focusable lights. What is needed is one device that solves many needs.
In each embodiment, the invention provides a light box which is preferably lightweight, foldable, modular and provides for soft projected light regardless of the lighting elements used. The invention, thought not limited to the use of nonfocusable lights, makes the use of inexpensive par lamps practical. Such lamps have an internal parabolic reflector which creates an extremely parallel beam of light. This xe2x80x9cpunchyxe2x80x9d light has been found to be ideal to project through diffusion mediums to soften the resultant light, but to retain much of the deep throw inherent in the lamp. It has also been found that when combining par lamps of various intensities (i.e., wide and medium beams at specific distances through diffusion frames), it is possible to create a light that is more consistent from upstage to downstage than a point source or more traditional lighting instruments. The foldable modular light diffusion box in all its forms uses this principle as its cornerstone and constructs devices useful for the motion picture and television industries as well as other uses. Although par lamps are existing technology and diffusing light through frames is not novel, both the concept and forms of the foldable modular light diffusion box create and contain light in a new way and of a quality, portability and consistency previously unavailable.
The invention further provides a substantially consistent light intensity in spite of the inverse square law. Light intensity from a point source drops off according to the inverse square law, i.e., intensity (i) at any distance (radius) (r) or from a point source of intensity (I) is given by the following equation: i=Ixc3x97(1/r2). However, in the invention, as noted above, consistency is maintained.
In one embodiment, the invention provides a modular light diffusion box which preferably is adapted to hold multiple lights. The box has a housing for channeling and controlling the light, the housing having two sides, a top and a bottom formed so as to be lightweight yet rigid or substantially rigid. The housing also has a channel or channels for supporting a diffusion frame or frames, or filters. In a preferred embodiment, the housing supports a bar, such as a standard 1xc2xdxe2x80x3 or 1⅝xe2x80x3 pipe (e.g., Speed Rail(trademark)) or other cross-member on which multiple lights may be mounted. In another preferred embodiment, the box is foldable and portable. It is also preferable that the box have an angle at its front end for directing light towards a set or stage when the box is elevated with respect thereto.
According to a modified embodiment of the invention, there is provided a foldable, modular light diffusion box containing an element for mounting multiple lights, and preferably containing multiple lights mounted therein. More preferably, these lights are high intensity but inexpensive, lightweight, and nonfocusable lights such as pars or par cans.
In a second embodiment, the invention provides a modular light diffusion box which has multiple lights disposed therein. Preferably, the lights are inexpensive, nonfocusable lights such as pars. The box has a housing or shell having four sides connected together for folding flat. The housing has an open front and an open back. One of the sides has an access door for opening and closing to selectively insert and replace diffusion screens or filters. A C-shaped yoke rotatably connects to two sides of the shell on the outside. The yoke has a standard pin for mounting to a stand or other standard female receptor. A rectangular reinforcing skeleton or frame mounts inside the shell and the lights are fixed to a standard pipe or rod mounted inside the rectangular frame.
In a third embodiment, the box is similar to the previous embodiment and has four lights therein. The front of the box has an angular face. The box is mountable to a green bed, scaffolding or otherwise supportable in the air by hanging it, rather than having a yoke. The box is constructed such that it may be placed adjacent other boxes to provide for a larger projected light. In this embodiment, the rectangular frame has two triangular frame elements connected to it, and the triangular elements support a standard rod for mounting the lights.
In a fourth embodiment, the box is rectangular and is hinged at the center of its short sides to collapse together. The box is adapted to be hung from a ceiling or other structure directly above the area to be lit. In a fifth version of this box, the shell may be soft, e.g., made of fabric and attached to, so as to hang from, the rectangular frame. The diffusion or gel frames are also attached to the rectangular frame at their corners by a chain or other flexible or collapsible attachment. The lights connect to a Socopex(trademark) connector or the equivalent. Yet another version of such a flexible, collapsible box has a rear cover which is perforated to provide for protection for the lights, which are built-in.
Still another version has built-in lights and a cover, a yoke mounted to the rectangle, and rigid members to hold the fabric instead of chain.